dependencies: Upgrade JavaScript dependencies.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

package.json

@@ -61,10 +61,10 @@
     "sortablejs": "^1.9.0",
     "sorttable": "^1.0.2",
     "source-sans-pro": "^3.6.0",
-    "spectrum-colorpicker": "https://github.com/andersk/spectrum.git#44dbe543919befc33e9160bf79f1395e8b9f6eb4",
+    "spectrum-colorpicker": "^1.8.1",
     "stacktrace-gps": "^3.0.4",
     "style-loader": "^1.0.0",
-    "terser-webpack-plugin": "^2.1.0",
+    "terser-webpack-plugin": "^3.0.3",
     "turndown": "^6.0.0",
     "underscore": "^1.9.1",
     "unorm": "^1.6.0",
@@ -80,18 +80,18 @@
     "@types/html-minifier": "^3.5.3",
     "@types/jquery": "^3.3.31",
     "@types/mini-css-extract-plugin": "^0.9.0",
-    "@types/node": "^13.7.0",
+    "@types/node": "^14.0.11",
     "@types/optimize-css-assets-webpack-plugin": "^5.0.1",
-    "@types/terser-webpack-plugin": "^2.2.0",
+    "@types/terser-webpack-plugin": "^3.0.0",
     "@types/underscore": "^1.8.18",
     "@types/webpack": "^4.4.32",
     "@types/webpack-dev-server": "^3.1.6",
-    "@typescript-eslint/eslint-plugin": "^2.7.0",
-    "@typescript-eslint/parser": "^2.7.0",
+    "@typescript-eslint/eslint-plugin": "^3.1.0",
+    "@typescript-eslint/parser": "^3.1.0",
     "babel-plugin-rewire-ts": "^1.3.3",
     "casperjs": "casperjs/casperjs",
     "difflib": "^0.2.4",
-    "eslint": "^6.6.0",
+    "eslint": "^7.2.0",
     "eslint-plugin-empty-returns": "^1.0.2",
     "jsdom": "^16.1.0",
     "nyc": "^15.0.0",

version.py

@@ -44,4 +44,4 @@ API_FEATURE_LEVEL = 9
 #   historical commits sharing the same major version, in which case a
 #   minor version bump suffices.
 
-PROVISION_VERSION = '85.1'
+PROVISION_VERSION = '86.0'